turning the front cam bolts out will raise the camber and caster.the rear bolt out will raise camber but lower caster.I always shoot for about 0 deg camber and about 3.0 deg positive caster.important to have equal readings side to side.camber is a tire wearing angle ,so that one is more important than caster.Positive Caster helps take the wander out.the more caster the more stable the car drives.I like about 1/8 inch toe in.Common caster spec for bmw's mercedes,other sport cars is in the neigborhood of 9-10 deg. positive caster.The only downfall with positive caster.Is with manual steering.makes slow speed turning alittle tougher.
Do alignments in this order.Tire psi,ride height,camber.caster and then toe.make sure the lower control arm bushing are good.Most common reason for too much neg camber.Yes the offset bushing will give you the adjustment you need.